The invention relates generally to porous reservoirs, and, more particularly, to an improved porous reservoir with an enhanced ability to retain a relatively large volume of a fluid or solid and release the fluid or solid into another environment. Even more specifically, this invention relates to three dimensional, self-sustaining, porous reservoirs.
Porous reservoirs formed from foam, cloth, non-woven fabrics, paper, sponges, bundled and/or bonded or unbonded natural or man-made fibers, porous metal or plastics, porous ceramic, cotton, linen, and similar fiber-based parts, pumice, asbestos, vermiculite, fused sand and fiber glass may absorb and/or hold various liquid or solid materials. In some applications, such “loaded materials” may be held in a porous article until the porous article is placed into a liquid that is miscible with the loaded material, whereupon the loaded material is released into and/or dissolved by the liquid. An exemplary application is one in which a porous reservoir is loaded with a concentrated cleaning fluid. The porous reservoir may be sized for insertion into a container of water or other liquid for release and dissolution of the cleaning fluid into the water.
In such applications, it is desirable to provide a reservoir that can hold a significant volume of loaded material and release that material as quickly as possible when the loaded reservoir is placed into the miscible liquid. Unfortunately, porous reservoirs generally exhibit a tradeoff between the volume of material that can be held in the porous reservoir (referred to herein as the material “transport volume”) and the rate at which the loaded fluid or solid material may be removed from the reservoir and dispersed or dissolved into the miscible fluid (the “dissolution rate”). In particular, reservoirs having a high transport volume generally have low dissolution rates. Conversely, reservoirs with large areas of exposed surface so as to produce high dissolution rates generally have comparatively low transport volumes and or exhibit leakage problems.
These problems tend to limit the usefulness of prior art reservoirs in applications where high transport volume and high dissolution rates are desirable.